Starting tomorrow, some 50,000 to 55,000 men 19 and 20 years old in the Washington area will be required to register for the draft.

Selective Service System officials emphasize that registration is merely a method of assembling a record of young men eligible to be drafted in the event of a national military mobilization. No one is being drafted now. But the officials caution that failure to register constitutes a federal offense and could result in a maximum penalty of five years' imprisonment and a $10,000 fine.

Young men can register during regular hours at any post office, or, if they are overseas, at any U.S. embassy or consular office.

Between July 21 and August 2, men born in 1960 should register during the first week and those born in 1961 during the second.

Further, men born in January, February or March of either year should register on Monday. Men with April, May and June birthdays should register on Tuesday. On Wednesday, men with July, August and September birthdays should register. And on Thursday, men born in October, November or December should register.

Fridays and Saturday mornings are makeup times for those who cannot register on their designated dates.

The only persons not required to register are women, members of the active armed forces, cadets or midshipmen at the military service academies and monimmigrant aliens (for example, members of diplomatic or trade missions and those on student or visitor visas).

Military reservists or members of the National Guard are required to register if they were born in 1960 or 1961.

Handicapped or disabled men are also required to register. Those confined to hospitals and panel or mental institutions must register within 30 days of their release.

If individuals are ill, or encounter a hardship that prevents them from registering on their assigned date, they can register as soon as they are able and avoid any penalty. Registration material will be available at all post offices.

At the post office, individuals will be given a green-and-white card that asks their name, birthdate, current mailing address, permanent mailing address, current phone number, Social Security number, signature and date signed. Individuals can check a box if they want the Selective Service to give their name, address and telephone number to armed services recruiters.

Men may also be asked to submit some form of identification, such as a driver's license, student identification card or birth certificate.

About 90 days later, each registrant will be mailed an acknowledgement detailing the information he entered on the cards, which by this time will have been placed in Selective Service files. A form will be sent with the letter so the individual can correct any mistakes in the data. No registration or draft card will be issued, but men should keep their verification letters as proof of registration.

If no acknowledgement is received soon after a 90-day period has passed, men should write the Selective Service System headquarters at 600 E St. NW, Washington, D.C. 20435.

Registrants are also required to notify the Selective Service if they change their address. Forms are available in all post offices.

For further information, call the Selective Service System office at 724-0419.