42 CFR § 408.27
Rounding the monthly premium
June 11, 2020
Any monthly premium that is not a multiple of 10 cents is rounded to the nearest multiple of 10 cents, and any odd mulitple of 5 cents is rounded to the next higher multiple of 10 cents.
[52 FR 48115, Dec. 18, 1987; 53 FR 4159, Feb. 12, 1988]