Part D late enrollment penalty per month: the amount for 1 to 120 uncovered months in 2026 and 2027

The month count carries from one year to the next, but the dollar amount does not. Each January the same count is multiplied by that year's base premium, so a 30-month gap that adds $11.70 to a 2026 premium adds $12.40 in 2027. CMS's reconsideration process does not cover that yearly change. The 2027 base premium was announced on July 28, 2026, and the Medicare.gov penalty page still shows the 2026 figure of $38.99, which applies through December 31, 2026.

The penalty also does not depend on which plan you pick. It is a share of a national number, not of your plan's own premium, so a plan that charges $0 a month still bills it, and moving to another plan leaves it where it was.

One percent of the base premium, once per full month

Three inputs make the number, and only one of them is yours. The first is the count of uncovered months. The second is the national base beneficiary premium for the year being billed. The third is the rounding rule, which is the same for everyone. Medicare.gov states the formula as 1 percent times the national base beneficiary premium, times the number of full, uncovered months you were eligible to join Medicare drug coverage but did not, with no other creditable coverage. The result is rounded to the nearest $0.10 and added to your monthly premium.

The statute behind it, section 1860D-13(b)(3) of the Social Security Act (42 U.S.C. 1395w-113), makes the penalty the greater of two amounts: what the Secretary finds actuarially sound for each uncovered month, or 1 percent of the base beneficiary premium for each such month. 42 CFR 423.286(d)(3)(i) repeats that wording. CMS applies the 1 percent figure. Its guidance to plans, Chapter 4 of the Medicare Prescription Drug Benefit Manual (section 20.4, CY 2026 version), says the penalty is 1 percent of the national base beneficiary premium for each full calendar month and is rounded to the nearest 10 cents.

The base premium is not what your plan charges. CMS describes it as the starting point from which each plan's own premium is built, and sets it by a statutory formula from the bids plans submit. The penalty uses the base premium of the year being billed: the CMS tip sheet says Medicare uses the current coverage year's base beneficiary premium, and Chapter 4 section 60.3 says the penalty amount changes at the start of each calendar year.

Take 14 months, the example Medicare.gov uses. The penalty is 14 percent. At the 2026 base premium, 0.14 x $38.99 = $5.4586, which rounds to $5.50. At the 2027 base premium, 0.14 x $41.33 = $5.7862, which rounds to $5.80. The monthly cost of that gap went up $0.30 without one month being added to the count.

Rounding to the dime is the only judgment call in the table that follows. Five months in 2026 is 0.05 x $38.99 = $1.9495. Rounded once, that is $1.90. A system that first rounded to the cent ($1.95) and then to the dime would bill $2.00. CMS's published examples round to the dime but do not settle the order: the Chapter 4 example prints 5 percent of $32.74 as $1.63, where the exact product is $1.637. The table rounds the exact product once, which is the plain reading of "rounded to the nearest 10 cents," and puts a dagger on the 11 cells that would move by ten cents under the other order. Where a cell has a dagger, the penalty letter from the plan is the figure that governs.

The penalty for 1 to 120 uncovered months, 2026 beside 2027

Each row multiplies the month count by the base premium and rounds once. The 2026 column uses $38.99 (CMS fact sheet, July 28, 2025). The 2027 column uses $41.33 (CMS notice of July 28, 2026, issued with its preliminary Part D bid information for 2027). The last column is the 2027 monthly amount times twelve. Months 1 to 36 are shown first and months 37 to 120 sit in the fold-out below them; for a longer gap, multiply the month count by 1 percent of the base premium and round once to the nearest ten cents.

Months 37 to 120 (3 to 10 years)

Uncovered months	Penalty, % of base premium	2026 per month ($38.99)	2027 per month ($41.33)	2027 per year
37	37%	$14.40	$15.30	$183.60
38	38%	$14.80	$15.70	$188.40
39	39%	$15.20	$16.10	$193.20
40	40%	$15.60	$16.50	$198.00
41	41%	$16.00	$16.90 †	$202.80
42	42%	$16.40	$17.40	$208.80
43	43%	$16.80	$17.80	$213.60
44	44%	$17.20	$18.20	$218.40
45	45%	$17.50 †	$18.60	$223.20
46	46%	$17.90	$19.00	$228.00
47	47%	$18.30	$19.40	$232.80
48	48%	$18.70	$19.80	$237.60
49	49%	$19.10	$20.30	$243.60
50	50%	$19.50	$20.70	$248.40
51	51%	$19.90	$21.10	$253.20
52	52%	$20.30	$21.50	$258.00
53	53%	$20.70	$21.90	$262.80
54	54%	$21.10	$22.30	$267.60
55	55%	$21.40	$22.70	$272.40
56	56%	$21.80	$23.10	$277.20
57	57%	$22.20	$23.60	$283.20
58	58%	$22.60	$24.00	$288.00
59	59%	$23.00	$24.40	$292.80
60	60%	$23.40	$24.80	$297.60
61	61%	$23.80	$25.20	$302.40
62	62%	$24.20	$25.60	$307.20
63	63%	$24.60	$26.00	$312.00
64	64%	$25.00	$26.50	$318.00
65	65%	$25.30	$26.90	$322.80
66	66%	$25.70	$27.30	$327.60
67	67%	$26.10	$27.70	$332.40
68	68%	$26.50	$28.10	$337.20
69	69%	$26.90	$28.50	$342.00
70	70%	$27.30	$28.90	$346.80
71	71%	$27.70	$29.30	$351.60
72	72%	$28.10	$29.80	$357.60
73	73%	$28.50	$30.20	$362.40
74	74%	$28.90	$30.60	$367.20
75	75%	$29.20	$31.00	$372.00
76	76%	$29.60	$31.40	$376.80
77	77%	$30.00	$31.80	$381.60
78	78%	$30.40	$32.20	$386.40
79	79%	$30.80	$32.70	$392.40
80	80%	$31.20	$33.10	$397.20
81	81%	$31.60	$33.50	$402.00
82	82%	$32.00	$33.90	$406.80
83	83%	$32.40	$34.30	$411.60
84	84%	$32.80	$34.70	$416.40
85	85%	$33.10	$35.10	$421.20
86	86%	$33.50	$35.50	$426.00
87	87%	$33.90	$36.00	$432.00
88	88%	$34.30	$36.40	$436.80
89	89%	$34.70	$36.80	$441.60
90	90%	$35.10	$37.20	$446.40
91	91%	$35.50	$37.60	$451.20
92	92%	$35.90	$38.00	$456.00
93	93%	$36.30	$38.40	$460.80
94	94%	$36.70	$38.90	$466.80
95	95%	$37.00	$39.30	$471.60
96	96%	$37.40	$39.70	$476.40
97	97%	$37.80	$40.10	$481.20
98	98%	$38.20	$40.50	$486.00
99	99%	$38.60	$40.90	$490.80
100	100%	$39.00	$41.30	$495.60
101	101%	$39.40	$41.70	$500.40
102	102%	$39.80	$42.20	$506.40
103	103%	$40.20	$42.60	$511.20
104	104%	$40.50 †	$43.00	$516.00
105	105%	$40.90	$43.40	$520.80
106	106%	$41.30	$43.80	$525.60
107	107%	$41.70	$44.20	$530.40
108	108%	$42.10	$44.60	$535.20
109	109%	$42.50	$45.00 †	$540.00
110	110%	$42.90	$45.50	$546.00
111	111%	$43.30	$45.90	$550.80
112	112%	$43.70	$46.30	$555.60
113	113%	$44.10	$46.70	$560.40
114	114%	$44.40 †	$47.10	$565.20
115	115%	$44.80	$47.50	$570.00
116	116%	$45.20	$47.90	$574.80
117	117%	$45.60	$48.40	$580.80
118	118%	$46.00	$48.80	$585.60
119	119%	$46.40	$49.20	$590.40
120	120%	$46.80	$49.60	$595.20

Source: CMS notice of July 28, 2026 (2027 base beneficiary premium $41.33); CMS fact sheet of July 28, 2025 (2026 base beneficiary premium $38.99); Medicare.gov, Part D late enrollment penalty (formula and rounding to the nearest $0.10). Computed from the exact product, rounded once, and checked November 3, 2026. † marks a cell that would be ten cents higher if the amount were rounded to the cent before the dime. Medicare figures, not your bill.

The exact penalty grows by 1 percent of the base premium with every month, which is 39 cents in 2026 (0.3899) and 41 cents in 2027 (0.4133). A full year of delay therefore adds about $4.68 a month in 2026 and $4.96 in 2027: 12 x 0.3899 = 4.6788, and 12 x 0.4133 = 4.9596. Between the two columns the difference comes only from the base premium, which rose $2.34, from $38.99 to $41.33. That is the 6 percent increase CMS shows as its calculation A, and it is why 36 months cost $14.00 in 2026 and $14.90 in 2027.

The rows for 1 and 2 months are in the table because they can occur, though a gap made of whole months cannot produce them. At the other end, nothing caps the count. Chapter 4 section 20.3 says there is no limit on the late enrollment penalty. CMS's initial enrollment period table in section 30.1.1 ends the period on May 15, 2006 for anyone whose Part A or Part B began on or before January 31, 2006. For such a person with no creditable coverage at any time and a plan starting January 1, 2027, the months from June 2006 through December 2026 number 247, a penalty of 247 percent: 2.47 x $41.33 = $102.0851, or $102.10 a month after rounding. That is a constructed illustration of the formula, not a case CMS describes.

Two clocks: the 63-day test and the month count

The penalty runs on two separate clocks. The first decides whether there is a penalty at all, and it counts days. The rule in 42 CFR 423.46(a) asks for a continuous period of 63 days or longer, starting after the end of your initial enrollment period, during which you were eligible for Part D, had no creditable drug coverage and were not enrolled in a plan. The statute puts it the same way in section 1860D-13(b)(2). The second clock decides the size of the penalty, and it counts months. The statute defines an uncovered month as any month beginning after the initial enrollment period ends unless you can demonstrate creditable coverage for any portion of that month (section 1860D-13(b)(3)(B)).

The day clock starts the day after the initial enrollment period ends. For someone entering Medicare at 65, that period is seven months long: it starts three months before the birthday month, includes the birthday month and ends three months after it. CMS's example in Chapter 4, section 30.1.1, is a 65th birthday on June 8, 2023: the period ran from March 1 to September 30, and day counting began on October 1. A birthday on the first of a month moves the whole window one month earlier. The clock stops on the day before drug coverage begins, and section 30.1 says days when you lived abroad, were incarcerated or were not lawfully present do not count.

A gap under 63 days costs nothing. CMS's guidance example has an enrollment period ending April 30, 2023, a plan starting July 1, and a gap of 61 days, so no penalty is assessed. Once a gap reaches 63 days, every uncovered month in it counts, including the first two. The CMS tip sheet answers the one-month question the same way: a person who waits one month has no penalty only because the gap never reaches 63 days.

Two whole calendar months run at most 62 days, in July and August or in December and January, so two whole uncovered months can never trip the day clock alone. Three consecutive whole months run at least 89 days, in February, March and April of a year that is not a leap year. When a gap is built from whole months, as it is when an enrollment period ends on the last day of a month and a plan starts on the first of another, the penalty therefore begins at 3 percent. The 1-month and 2-month rows matter only when creditable coverage ends partway through a month.

Show the day counts behind this figure

Period (2027)	Days	Counts toward the penalty?
Jan 1 to Jan 15	15	No: creditable coverage
Jan 16 to Jan 31	16	Gap days, but January is not an uncovered month
Feb 1 to Feb 28	28	Yes: uncovered month 1
Mar 1 to Mar 31	31	Yes: uncovered month 2
Gap total	75	63-day test met

Suppose employer drug coverage that counts as creditable ends on January 15, 2027, and a Part D plan starts on April 1. The gap runs January 16 through March 31, which is 16 + 28 + 31 = 75 days. That is past 63, so a penalty applies. But January had creditable coverage for part of the month, so by the statute's wording it is not an uncovered month. Only February and March count: 2 percent, and 0.02 x $41.33 = $0.8266, or $0.80 a month. If the same coverage had ended on January 31, a plan starting April 1 would leave 28 + 31 = 59 days and no penalty at all.

Source: 42 CFR 423.46(a); Social Security Act section 1860D-13(b)(2) and (b)(3)(B) (42 U.S.C. 1395w-113, current through Public Law 119-136, October 22, 2026); CMS Chapter 4 guidance, sections 20.3, 30.1 and 30.2 (CY 2026 version). Day counts and amounts computed November 3, 2026 at the 2027 base premium of $41.33. Illustrations with stated dates, not bills.

The first row follows CMS's own 61-day example and the second follows its five-month example, with the dates moved to 2026 and 2027. The mid-month row is a reading of the statute, not a CMS example: CMS's guidance speaks of full calendar months and its examples all start and stop at month boundaries. The plan's notice lists the gap dates it took from CMS records, and those dates are what an attestation or an appeal corrects.

What counts as drug coverage that stops the clock

Coverage stops both clocks only if it is creditable, which means it is expected to pay on average at least as much as Medicare's standard drug coverage. The statute lists the types in section 1860D-13(b)(4): a Part D or Medicare Advantage drug plan, Medicaid, a group health plan including the Federal Employees Health Benefits program and qualified retiree drug plans, a State Pharmaceutical Assistance Program, veterans' coverage, a Medigap policy that provides drug benefits, military coverage including TRICARE, and other coverage the Secretary approves. 42 CFR 423.56(b) adds individual health insurance with outpatient drug coverage that is not an excepted benefit, Indian Health Service, tribal and urban Indian programs, PACE, cost plans and state high-risk pools.

Being in one of those categories is not enough. Each non-Medicare plan must test its drug benefit against the standard Part D benefit and tell its members whether it passed. Under 423.56(f), notices go out before the initial enrollment period, before the effective date of enrollment and on any change, before the annual election period that starts October 15, and on request. A person who cannot find the notice can ask the plan for it; the CMS tip sheet suggests contacting the plan. Chapter 4 section 20.1 lists what does not count: prescription drug discount cards, free clinics and drug discount websites. The guide to whether a drug discount card counts toward your deductible covers the same boundary from the pharmacy counter.

Two things change for 2027, both from the April 6, 2026 final rule (91 FR 17384, CMS-4208-F3 and CMS-4212-F), which took effect June 1, 2026 and applies to coverage beginning January 1, 2027. The first is the test that group health plans not receiving the retiree drug subsidy may use in place of actuarial testing, the simplified determination. The rule writes into 423.56(a)(2) a requirement that the plan be designed to pay on average at least 73 percent of participants' drug expenses for 2027, up from 72 percent in 2026. A person never computes this; it is the employer or union that attests. The second change is in 423.56(b)(3): the group health plan coverage that can be creditable now excludes account-based medical plans, such as health reimbursement arrangements, which is also why they no longer have to disclose creditable status. CMS reasoned in the rule that account-based entities do not offer drug coverage. A reimbursement account is therefore not required to send a creditable-coverage notice, and the notice to look for comes from the plan that actually covers prescriptions.

One more category is easy to miss. CMS's CY 2026 version of Chapter 4, released with an HPMS memo on July 22, 2025, adds language that all prior or current drug coverage under the Indian Health Service, a tribe or tribal organization or an urban Indian program is creditable coverage, and that generally no penalty should be assessed. If a person was not adequately informed that a plan's coverage was not creditable, 42 CFR 423.56(g) and the statute allow an application to CMS to have that coverage treated as creditable. 423.46(c) ties the reconsideration process to that provision, and the CMS form described below has a box for it.

Months that stop counting: Extra Help, turning 65 and dropped plans

The penalty is not always a lifetime fixture. Three events remove it or reduce the count, and the rules are specific enough to price.

Extra Help comes first. The statute says that in no case is a subsidy-eligible individual subject to a late enrollment penalty (section 1860D-13(b)(8)), and 42 CFR 423.780(e) repeats it. Chapter 4 explains the mechanics. If you have Extra Help when you enroll, the plan does not count days at all. If you had Extra Help earlier and do not now, days are counted from the day after your Extra Help ended, and only from the most recent Extra Help period. If you are already paying a penalty and become eligible for Extra Help, section 50.4 says the penalty is removed and the uncovered months reset to zero from the start of your Extra Help eligibility, although you still owe any penalty that was unpaid before that date. The reset can be undone: section 50.4.1 says that if a person was reported as eligible in error, CMS re-establishes the penalty and applies the earlier months retroactively.

CMS's tip sheet works a full example, which this table re-prices.

Source: CMS Partner Tip Sheet, The Part D Late Enrollment Penalty (CMS Product No. 11222-P, March 2024), example 3. The tip sheet prices the 12 months at $4.20 for 2024 (12% of $34.70). Re-priced here: 12% of $38.99 is $4.6788, so $4.70 in 2026, and 12% of $41.33 is $4.9596, so $5.00 in 2027. Computed November 3, 2026. Medicare figures, not your bill.

Eleven of the 23 months Mrs. Kim spent without a plan never count, so her penalty is 12 percent, not 23 percent. At the 2027 base premium, 23 months would be $9.50 a month, against $5.00 for the 12 that count.

A subsequent initial enrollment period is the second event. Someone who has Medicare on the basis of disability and turns 65 gets a new seven-month period. Section 20.6 of Chapter 4 says a penalty already assessed is not billed after that point, and section 30.1.3 says it ends on the day before the new period begins, with the uncovered months reset to zero. CMS's example is a person with six uncovered months who turned 65 in May 2021: the count reset on February 1, 2021, and a later gap was counted only from the end of the new period, giving four months, with the earlier six no longer added.

Dropping Part D is the third. Section 20.6 says that a person who is assessed a penalty and drops Part D does not continue to pay it, but if the person enrolls again the earlier penalty returns and may be higher for the newest gap. CMS's example adds the gaps: 12 uncovered months, then a return, then 24 more, produces a penalty on 36 uncovered months. At the 2027 base premium that is $14.90 a month, which is the 36-month row of the table, not the $5.00 the first gap alone would cost.

Disputing the amount: the plan's attestation, then the CMS reviewer

The dispute has two stages, and the first one is easy to miss because it arrives as a form rather than a letter about money. When a plan accepts your enrollment, it checks CMS records for a gap of 63 days or longer. If it finds one, Chapter 4 section 40 requires it to notify you within seven calendar days, explain the gap dates and send an attestation of prior drug coverage. You have 30 calendar days to return it. Your signature is all that is required. The plan may not demand proof at this stage. If you do not respond, the gap is treated as a period without creditable coverage, but the plan must still accept an attestation received up to 60 days after the deadline and adjust the count. Information that arrives later than that is not used, and the plan tells you so.

The second stage is the penalty letter. Within 10 calendar days of having what it needs, the plan sends notice of a new or increased penalty (section 70.1), with the gap dates, the premium split into its two parts, a reconsideration notice and a request form. For a new or increased penalty the letter must state the filing deadline: 60 calendar days from the date of the letter. It must also say that you keep paying the penalty while the request is reviewed.

Source: CMS Prescription Drug Benefit Manual Chapter 4 (CY 2026 version, issued July 22, 2025), sections 40, 70.1 and 80; CMS Partner Tip Sheet 11222-P (March 2024); CMS, Late Enrollment Penalty (LEP) Appeals page (last modified September 10, 2024); CMS Part D LEP Reconsideration Request Form C2C, v1.0. Checked November 3, 2026.

The reviewer is not the plan. 42 CFR 423.46(c) says a person determined to be subject to the penalty may request reconsideration consistent with 423.56(g), and that the review is conducted by CMS or an independent review entity under contract to CMS. CMS's appeals page says an independent review entity under contract with Medicare conducts the reconsideration, and the Part D LEP Reconsideration Request Form C2C names C2C Innovative Solutions, Inc. as that contractor. The form lists the circumstances it will review: you had creditable coverage, with copies of a creditable-coverage notice or similar proof from an employer, union, Department of Veterans Affairs or Indian Health Service plan; you had drug coverage but never received a notice that clearly said whether it was creditable; you were not eligible to enroll for part of the period, for example because you lived outside the United States; you could not enroll because of a serious medical emergency, such as an unexpected hospitalization; or you have or had Extra Help, with dates. The form asks for a signature and says not to send original documents. A relative or a doctor can file only as an appointed representative, using the attached appointment form.

Four limits apply. First, you pay while you wait: the tip sheet says the penalty must be paid with the premium during the review, and Chapter 4 section 80.1.4 says the plan keeps billing, and Social Security keeps withholding, until the decision is processed. Second, the review is final: 423.46(c) says decisions are not subject to appeal, though CMS may review and revise them. Third, the review can move the count in either direction. Section 50.2.3 says reconsideration decisions may uphold, increase, decrease or eliminate the number of uncovered months. Fourth, the yearly change from the base premium is outside the process entirely, because section 60.3 says reconsideration is not available for adjustments based on the yearly change to the national base beneficiary premium.

The money at stake shows why the months are worth checking. In 2027 each uncovered month removed from the count lowers the exact penalty by 41 cents, and a 30-month penalty of $12.40 a month becomes $12.00 at 29 months. If the plan's gap dates include a period in which you had an employer drug plan, a VA benefit or Extra Help, the month count is where the amount can change. The general sequence for challenging a plan decision is in the guide to appealing a health insurance denial, though the penalty has its own route and its own form.

Four base premiums and the 6 percent ceiling

The base premium is the only part of the formula that changes without any action on your part, so its history is the best guide to what the same months cost over time.

Source: CMS Partner Tip Sheet 11222-P (March 2024); CMS fact sheet of July 28, 2025; CMS memo and fact sheet of July 28, 2026. No 2025 figure is shown because none was read. Computed November 3, 2026. Medicare figures, not your bill.

How 2027 was set is on the face of CMS's July 28, 2026 memo. The Inflation Reduction Act limits the base premium for 2024 through 2029 to the lesser of two calculations. Calculation A is the prior year's base premium increased by 6 percent: $38.99 x 1.06 = $41.33. Calculation B is the formula result, a beneficiary premium percentage applied to the national average monthly bid amount, which came to $94.06. The lesser, $41.33, is the 2027 base premium. The national average monthly bid amount itself is $296.05. In other words, the 6 percent ceiling is what is holding the 2027 penalty down: without it, the formula result would have more than doubled the number.

That is the 2027 arithmetic only. The ceiling is written for 2024 through 2029. After that, the statute's formula for 2030 and later years differs, and CMS has published no base premium beyond 2027. The totals below therefore use stated assumptions rather than forecasts. CMS also announced on July 28, 2026 that the Part D Premium Stabilization Demonstration for stand-alone plans ends after 2026. CMS describes it as a voluntary demonstration for stand-alone plans meant to ease premium volatility, so it concerns plan premiums rather than the penalty formula. CMS's September 28, 2026 press release on 2027 coverage projects the average stand-alone drug plan premium at $36 for 2027, up from $35.09 in 2026, and does not restate a different base premium.

Thirty uncovered months over ten years and over twenty

The penalty is a monthly charge with no end date, so the useful total is cumulative. Take a person with 30 uncovered months who stays enrolled in Part D without interruption, never qualifies for Extra Help and never has a subsequent enrollment period. Every figure below is arithmetic on stated inputs, in current dollars, with no discounting, and each year's monthly amount is rounded to the dime before it is multiplied by twelve.

At the 2027 base premium held flat, 30 percent of $41.33 is $12.3990, which rounds to $12.40 a month. Twelve payments are $12.40 x 12 = $148.80 a year. Over ten years that is $148.80 x 10 = $1,488.00, and over twenty years $2,976.00. The table runs the same arithmetic for other month counts.

Source: CMS notice of July 28, 2026 (2027 base premium $41.33); formula per Medicare.gov and CMS Chapter 4 section 20.4. Assumptions for the totals: continuous enrollment from 2027, base premium held at $41.33, no Extra Help, no change in the month count. Computed November 3, 2026. Not a forecast and not your bill.

Holding the base premium flat is the simplest case, and the formula does not require it: the 2027 rule is a lesser-of test, and CMS has published nothing for later years. The next table lets the premium move, still for 30 uncovered months. The first scenario is the flat case. The second raises the base premium 3 percent a year from 2028 and rounds it to the cent each year: 2028 is $42.57, and the 30-month penalty steps to $12.80. The third applies the most the 2024 through 2029 ceiling allows in the two remaining years it covers, 6 percent, which gives $43.81 in 2028 and $46.44 in 2029, and then holds the premium flat because no rule beyond 2029 is known.

Source: arithmetic on the CMS 2027 base premium of $41.33, using the stated growth assumptions. CMS has published no base premium after 2027, and the 6 percent ceiling (CMS notice of July 28, 2026) is written for 2024 through 2029. Computed November 3, 2026. These are not forecasts.

The flat case costs $1,488.00 over ten years; the 3 percent path costs $1,708.80, which is $220.80 more for the identical 30 months. Over twenty years the 3 percent path reaches $4,003.20, against $2,976.00 flat. None of those paths changes the count of 30 months. Everything that varies comes from the base premium, which no reconsideration can touch, so the month count is the one input that the process lets anyone examine.

How the penalty reaches your bill

The penalty is part of the Part D premium. Chapter 4 section 20.5 says a plan with a $0 premium still bills it unless the person has Extra Help, and that it is paid the same way as the premium, including through withholding from a Social Security benefit. The same section notes that Social Security permits withholding of premiums, penalty included, only when the monthly amount does not exceed $300. A person who does not pay can be disenrolled for non-payment of premiums, because the penalty is treated as part of the premium (sections 20.5 and 80.2).

The penalty therefore sits outside two mechanisms that readers often expect to cover it. The out-of-pocket cap counts what you pay for covered drugs at the pharmacy, not premiums, as the Part D out-of-pocket cap guide explains, so reaching the cap does not stop the penalty. The Medicare Prescription Payment Plan spreads pharmacy costs over monthly bills, and the plan premium is billed separately from it. Extra Help is the program that removes the penalty, with the months before it no longer counted, and the income limits for the state programs that carry Extra Help with them are in the guide to Medicare Savings Programs. The whole set of drug-cost guides is gathered on the prescription drug costs topic page.

A separate penalty exists for Part B, with its own formula, and Medicare.gov explains it on its page about avoiding late enrollment penalties. It is outside the arithmetic here. Plan comparisons and enrollment timing are outside what MyCarePrice prices; Medicare.gov and 1-800-MEDICARE are the places for that.

Penalty questions people bring to a plan or to Medicare

Notices and rules the penalty arithmetic rests on

• CMS, Medicare Part D 2027 National Average Monthly Bid Amount Information (July 28, 2026): 2027 base beneficiary premium $41.33, national average monthly bid amount $296.05, 6 percent annual limit for 2024 through 2029, end of the premium stabilization demonstration. Checked November 3, 2026.
• CMS, Annual Release of Part D National Average Monthly Bid Amount and Other Part C and D Bid Information (memo of July 28, 2026): calculation A ($38.99 x 1.06 = $41.33) and calculation B ($94.06). Checked November 3, 2026.
• CMS, 2026 Medicare Part D Bid Information and Part D Premium Stabilization Demonstration Parameters (July 28, 2025): 2026 base beneficiary premium $38.99. Checked November 3, 2026.
• CMS, Medicare Advantage and Medicare Prescription Drug Programs Expected to Remain Stable in 2027 (September 28, 2026): projected average stand-alone premium of $36 for 2027. Checked November 3, 2026.
• Medicare.gov, Part D late enrollment penalty: the 1 percent formula, rounding to the nearest $0.10, the 14-month example, Extra Help. Checked November 3, 2026.
• CMS, Medicare Prescription Drug Benefit Manual, Chapter 4, Creditable Coverage Period Determinations and the Late Enrollment Penalty Guidance (CY 2026 version, revised July 22, 2025), sections 20.1 to 20.6, 30.1 to 30.2, 40, 50.2.3, 50.4, 60.3, 70.1 and 80. CMS's release memo says it does not change policy. The latest version listed on CMS's creditable coverage page when checked on November 3, 2026.
• CMS, Partner Tip Sheet: The Part D Late Enrollment Penalty (CMS Product No. 11222-P, March 2024): current-year base premium rule, 2023 and 2024 base premiums, worked examples, reconsideration steps. Checked November 3, 2026.
• CMS, Late Enrollment Penalty (LEP) Appeals and the Part D LEP Reconsideration Request Form C2C (v1.0): 60-day filing, 90-day decision, listed circumstances. Checked November 3, 2026.
• Electronic Code of Federal Regulations, 42 CFR 423.46, 423.56, 423.286 and 423.780, current through October 30, 2026. Checked November 3, 2026.
• Office of the Law Revision Counsel, 42 U.S.C. 1395w-113 (Social Security Act section 1860D-13), subsections (a) and (b), current through Public Law 119-136 (October 22, 2026). Checked November 3, 2026.
• Federal Register, Medicare Program; Contract Year 2027 and Certain Contract Year 2026 Policy and Technical Changes (91 FR 17384, April 6, 2026): 423.56(a) simplified determination at 73 percent for 2027, 423.56(b)(3) account-based plans, effective June 1, 2026 and applicable January 1, 2027. Checked November 3, 2026.

General billing information, not medical, legal or insurance advice. Penalty amounts are arithmetic on federal base premiums. Confirm your price in writing before service.